There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
There's a mysterious dwarf planet between Mars and Jupiter called 'Ceres' which has never been visited by spacecraft or photographed in detail, however, Earth-bound telescopes reveal a large bright shining spot on the surface of this planet, the origin and nature of which are unknown.
5
The typical spec of dust that you see floating in the air is half way in size between the Earth and a subatomic particle.
131
The Earth gets heavier each day by tons, as meteoric dust settles on it.
118
On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
7
The heart of an astronaut actually gets smaller when in outer space.
216
Venus is the only planet that rotates clockwise.
310
If you were to cry in space, the tears would form a bubble in your eye until it's so big it moves to another spot on your face.
10